Mildew is an important issue in grain storage, due to the very expensive losses that can arise due to grain spoilage by mildew. Monitoring the conditions which allow mildew to develop is important ...and current monitoring technology cannot readily, or safely, be used for internal humidity monitoring of the very large quantities of grain kept in storage. In this work, a quasi-distributed, tailored fiber optic temperature and humidity sensor system suitable for use in the large granaries has been developed. Dust from the grain is a major issue and the sensor system copes well with this. Various sensor designs have been evaluated and building on prior work, a design with a humidity sensitivity of 5.8pm/%RH, a measurement error of 2%RH, and response time of 4.3 minutes, which is more than adequate for the applications discussed has been developed. Field-testing of the sensor system was carried out at a major storage facility in China, monitoring over an extended period of 4 months, giving results consistent with the outputs from other point sensors currently used in the granary. The fiber optic sensor system developed shows the additional advantages that as a quasi-distributed system, it can be used to record the temperature and humidity distribution across a longitudinal section of the large size of the grain pile, in real time, reflecting the changes in the internal moisture content. The results obtained showed the sensor system has broad market application prospects in this and other important areas of agricultural and food storage.
In this paper, an all fiber optic sensor based on a Mach-Zehnder interferometer (MZI) has been proposed for the simultaneous measurement of underwater pressure and temperature, utilizing a dual-mode ...fiber (DMF) which has been specially designed, and supporting only the LP 01 and LP 02 modes propagating in the fiber. In this design, an in-line MZI sensor that was constructed by splicing a DMF between two pieces of single mode fibers, shows a critical wavelength (CWL) which exists in the transmission spectrum of the LP 01 -LP 02 mode interference. Since the two peaks, located closest to the CWL (and from both lower and higher wavelengths), shift in opposite directions and show different sensitivities under temperature and water pressure variations, the DMF-MZI sensor is capable of measuring both the water pressure and the temperature simultaneously. The CWL-based interference spectrum is stable with the variation of underwater salinity or impurities seen around the fiber surface and independent of the polarization states of the transmission light. As a result, in the operation of the DMF-MZI sensor, underwater pressure and temperature sensitivities increase significantly, when the peak wavelengths are close to that of the CWL. A theoretical analysis has been developed and used to predict that the sensitivities of this specific DMF-MZI structure which can be further improved by increasing the physical length of the DMF and by adjusting the position of the first left/right peak to be closer to the critical wavelength. This co-located, multi-parameter all-fiber sensor developed in this way and showing relatively high sensitivity is easy to implement in the underwater environment. It does not require a complex shell design and the peaks nearest to a CWL are convenient, allowing easy identification and detection, thereby providing a large measurement range to satisfy the requirements of practical marine and fresh water measurements.
The optical attractive force in tapered single-mode fibers (SMFs) is usually uniformly distributed around the tapered section and has been found to be important for trapping and manipulating targeted ...atoms and nanoparticles. In contrast, a peculiar phenomenon of the evanescent field splitting along the azimuth axis can be experimentally observed by tapering a weakly-coupled MCF into a strongly-coupled MCF to generate supermode interference. Moreover, the supermode interference produces a hexagonally distributed evanescent field and its six vertices give rise to the multiline optical attractive force. For such spectral resonances, the optimum extinction ratio for the transmission dips is given by 47.4 dB, this being determined using an index liquid to cover the tapered MCF. The resonant dips move to a greater extent at longer wavelengths, with the optimum tuning efficiency of 392 nm/RIU for index sensing. The split evanescent fields respectively attract the excited upconversion nanoparticles in the liquid to be linearly aligned and running down the tapered region over the fiber surface, emitting green light with 60° symmetry. The charged nanoparticles were periodically self-organized, with a period of around 1.53 µm. The parallel lines, with 60° rotational symmetry, can be useful for (1) indicating the exact locations of the side-cores or orientations of the tapered MCF; (2) as precision alignment keys for micro-optical manipulation; and (3) enhancing the upconversion light, or for use in lasers, coupling back to the MCF. The split evanescent fields can be promising for developing new evanescent field-based active and passive fiber components with nano-structures.
Acoustic manipulation techniques have gained significant attention across various fields, particularly in medical diagnosis and biochemical research, due to their biocompatibility and non-contact ...operation. In this article, we review the broad range of biomedical applications of micro/nano-motors that use acoustic manipulation methods, with a specific focus on cell manipulation, targeted drug release for cancer treatment and genetic disease diagnosis. These applications are facilitated by acoustic-propelled micro/nano-motors and nanoparticles which are manipulated by acoustic tweezers. Acoustic systems enable high precision positioning and can be effectively combined with magnetic manipulation techniques. Furthermore, acoustic propulsion facilitates faster transportation speeds, making it suitable for tasks in blood flow, allowing for precise positioning and in-body manipulation of cells, microprobes, and drugs. By summarizing and understanding these acoustic manipulation methods, this review aims to provide a summary and discussion of the acoustic manipulation methods for biomedical research, diagnostic, and therapeutic applications.
This study aims to characterize the rate of two specific resistance genes (KPC and NDM-1) and determine the route of transmission between the sites to implement infection control measures ...effectively.
This study was carried out at Viet Duc hospital in Vietnam. Bacterial isolates (Klebsiella pneumoniae) were collected between January 2018 and June 2019. Bacterial strains and antimicrobial susceptibility testing were performed in the VITEK 2 system.
A total of 100 samples from 25 patients were taken. From each patient, we collected 4 samples from 4 sites. 25 isolated strains resisted 100% to amoxicillin/acid clavulanic, piperacillin/Tazobactam, and antibiotics in the cephalosporine group. Particularly in the carbapenem group, they resisted 100% to ertapenem, 96% to imipenem, and eropenem (rest was intermediate level). They have 76% sensitivity to aminoglycosides, 76% to amikacin, 60% to gentamycin, and 60% to tigecycline. Klebsiella pneumoniae carbapenemase (KPC) (+) was 24% and NDM-1 (+) was 28%. There was no case in all four sites. Positive-KPC strains were mainly in two sites (4/6 = 66.67%) and positive-NDM-1 strains were mainly in three sites (4/7 = 57.14%). Negative to both KPC and NDM-1 strains were in one site (4/12 = 33.3%) and two sites (6/12 = 50%).
The rate of KPC and NDM-1 was 24% and 28%. In accordance with high antibiotic resistance rates to common antibiotics used in Vietnam, the high rate of transmission possibility between the sites contributed to strengthen the implementation of infection control measures in the ICU setting.
This paper studied the relationship between the temperature/strain wavelength sensitivity of a fiber optic in-line Mach-Zehnder interferometer (MZI) sensor and the wavelength separation of the ...measured wavelength to the critical wavelength (CWL) in a CWL-existed interference spectrum formed by interference between LP 01 and LP 02 modes. The in-line MZI fiber optic sensor has been constructed by splicing a section of specially designed few-mode fiber (FMF), which supports LP 01 and LP 02 modes propagating in the fiber, between two pieces of single-mode fiber. The propagation constant difference, <inline-formula> <tex-math notation="LaTeX">\Delta \beta </tex-math></inline-formula>, between the LP 01 and LP 02 modes, changes non-monotonously with wavelength and reaches a maximum at the CWL. As a result, in the sensor operation, peaks on the different sides of the CWL then shift in opposite directions, and the associated temperature/strain sensitivities increase significantly when the measured wavelength points become close to the CWL, from both sides of the CWL. A theoretical analysis carried out has predicted that with this specified FMF sensor approach, the temperature/strain wavelength sensitivities are governed by the wavelength difference between the measured wavelength and the CWL. This conclusion was seen to agree well with the experimental results obtained. Combining the wavelength shifts of the peaks and the CWL in the transmission spectrum of the SFS structure, this paper has shown that this approach forms the basis of effective designs of high sensitivity sensors for multi-parameter detection and offering a large measurement range to satisfy the requirements needed for better industrial measurements.
The influence of the high index ring layer (HIRL) in a tapered fiber Mach-Zehnder interferometer (MZI) on the interference observed, and thus on its potential applications in temperature sensing, has ...been investigated. The MZI was comprised of a tapered Ring Core Fiber (RCF), spliced between two single mode fibers (SMF). Since part of core mode from the SMF was converted into cladding modes in the RCF, due to the mismatch in the cores between the RCF and SMF, the residual power enters and then propagates along the center of the RCF (silica). The difference in phase between the radiation travelling along these different paths is separated by the HIRL to generate an interference effect. Compared with fiber interferometers based on core and cladding mode interference, the thin fiber HIRL is capable of separating the high order cladding modes and the silica core mode, under grazing incident conditions. Therefore, the optical path difference (OPD) and the sensitivity are both substantially improved over what is seen in conventional devices, showing their potential for interferometric temperature sensor applications. The optimum temperature sensitivity obtained was 186.6 pm/°C, which is ∼ 11.7 times higher than has been reported previously.
The work presents the magnetocaloric effect and critical behavior of monoclinic polycrystalline Pr0.7CaxSr0.3-xMnO3 prepared by solid state reaction. The ferromagnetic-paramagnetic phase transition ...temperature decreases from 267, 202, 138 to 126 K with increasing doping concentration from x=0 to 0.3. The maximum values of entropy change appear near the transition phase points and were found to be 6.4, 7.2, 3.9 and 4.0 J.kg-1.K-1 with 5 Tesla of field change for x=0-0.3, respectively. However, the shift to the higher temperature side with the increasing field change was observed clearly in sample x=0.1. Besides, the considering magnetic phase transition of samples based on Banerjee’s criterion showed a first-order phase transition in Pr0.7Ca0.1Sr0.2MnO3 (x=0.1) while samples with x=0, x=0.2 and 0.3 exhibited a second-order phase transition.
Abstract Objective Epithelial ovarian cancer (EOC) is one of the most common cancers in women worldwide but relatively little is known about its molecular pathogenesis. MicroRNAs, which regulate gene ...expression post-transcriptionally, have emerged as key players in tumorigenesis. The present study aims to investigate the dysregulation of miR-145 in EOC. Methods miRNA expression was assessed in EOC tissues and cell lines by quantitative reverse transcription (RT)-PCR. Xenograft mouse model was used for evaluation of the effect of miR-145 on tumor growth. Cell proliferation, colony formation assays, invasion assay, flow cytometry, Western blot and gene expression analysis were used for identification of the functional role of miR-145 in EOC cells. Luciferase reporter assay was used to confirm the interaction between miR-145 and its target mRNA 3′-UTR. Results miR-145 expression was downregulated in EOC tissues and cell lines as compared with normal ovarian tissues. Transfection of miR-145 agomiR significantly inhibited the proliferation, colony forming ability, invasiveness and in vivo tumorigenicity of EOC cells. Transfection of agomiR-145 into EOC cells also markedly induced apoptosis. Furthermore, computational algorithm combined with luciferase reporter assays identified TRIM2 as the direct target of miR-145 in EOC cells. To this end, agomiR-145 downregulated TRIM2 to derepress Bim (a pro-apoptotic Bcl-2 family member degraded by TRIM2). Conclusions These data confirmed the tumor-suppressing function of miR-145 in EOC and identified TRIM2 as a new miR-145 target. In vivo delivery of agomiR-145 might be a feasible approach for miRNA-directed cancer therapy.
Kidney transplantation is the major therapeutic option for end-stage kidney diseases. However, acute rejection could cause allograft loss in some of these patients. Emerging evidence supports that ...microRNA (miRNA) dysregulation is implicated in acute allograft rejection. In this study, we used next-generation sequencing to profile miRNA expression in normal and acutely rejected kidney allografts. Among 75 identified dysregulated miRNAs, miR-10b was the most significantly downregulated miRNAs in rejected allografts. Transfecting miR-10b inhibitor into human renal glomerular endothelial cells recapitulated key features of acute allograft rejection, including endothelial cell apoptosis, release of pro-inflammatory cytokines (interleukin-6, tumor necrosis factor α, interferon-γ, and chemokine (C–C motif) ligand 2) and chemotaxis of macrophages whereas transfection of miR-10b mimics had opposite effects. Downregulation of miR-10b directly derepressed the expression of BCL2L11 (an apoptosis inducer) as revealed by luciferase reporter assay. Taken together, miR-10b downregulation mediates many aspects of disease pathogenicity of acute kidney allograft rejection. Restoring miR-10b expression in glomerular endothelial cells could be a novel therapeutic approach to reduce acute renal allograft loss.
•miR-10b was the most downregulated microRNAs in acutely rejected renal allografts.•miR-10b downregulation triggered glomerular endothelial cell apoptosis.•miR-10b downregulation induced release of pro-inflammatory cytokines.•miR-10b downregulation derepressed its pro-apoptotic target BCL2L11.
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